I have a lot of dust in my little basement wood shop. New off-the-shelf ceiling mounted filtration units are a bit expensive. So before buying one I did an easy little build using an old window fan and some scrap wood that was laying around. So far I've been pleasantly impressed. It moves a good amount of air, is very quiet, and doesn't take up a lot of room. Time will tell just how efficient it is, but for now it seems okay.
For the filtration I used two cheap blue filters 12" x 24" x 1", and then one good 3M filter of the same size. I wired in a switch and screwed the box to the ceiling joists.
The video shows the full build. The whole project only took a few hours.
Thanks for taking a look.